Conventional tape layup methods and resulting laminated composite materials have important applications to industrial manufacturing of various articles and structures. For example, US Patent Application Publication US 2012/0177872, which is incorporated herein by reference, discloses state-of-the-art composite laminated structures and methods for manufacturing and using the same.
Traditional laminates are built up by uni-tape (i.e., tape with unidirectional fiber orientation) following 4-axis layup, one each along 0, ±45, and 90 degree directions. Since each layer is built up with uni-tape, each layer has parallel tape placed side-by-side with no cut fibers. Automated tape laying (ATL) machine normally uses 6″ or 12″ wide tape of unidirectional composites. If a laminate design calls for 4 ply angles, like 0°, +45°, −45°, 90°, the tape laying will need to follow 4 different axes, one for each ply orientation, and repeat the layup as required. With bi-axial C-Ply such as [0/45] that is normally made with one half the thickness of uni-tape, 2-axis layup will form the same [π/4] quasi-isotropic laminate, simplifying the layup process. Most ATL made today can handle only one type of tape at a time. Thus, 2-axis layup processes that require two distinctive types of tapes are problematic.